summaryrefslogtreecommitdiffstats
path: root/fs/nfs/nfs4super.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/nfs/nfs4super.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/nfs/nfs4super.c')
-rw-r--r--fs/nfs/nfs4super.c314
1 files changed, 314 insertions, 0 deletions
diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c
new file mode 100644
index 000000000..d09bcfd7d
--- /dev/null
+++ b/fs/nfs/nfs4super.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com>
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mount.h>
+#include <linux/nfs4_mount.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_ssc.h>
+#include "delegation.h"
+#include "internal.h"
+#include "nfs4_fs.h"
+#include "nfs4idmap.h"
+#include "dns_resolve.h"
+#include "pnfs.h"
+#include "nfs.h"
+
+#define NFSDBG_FACILITY NFSDBG_VFS
+
+static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc);
+static void nfs4_evict_inode(struct inode *inode);
+
+static const struct super_operations nfs4_sops = {
+ .alloc_inode = nfs_alloc_inode,
+ .free_inode = nfs_free_inode,
+ .write_inode = nfs4_write_inode,
+ .drop_inode = nfs_drop_inode,
+ .statfs = nfs_statfs,
+ .evict_inode = nfs4_evict_inode,
+ .umount_begin = nfs_umount_begin,
+ .show_options = nfs_show_options,
+ .show_devname = nfs_show_devname,
+ .show_path = nfs_show_path,
+ .show_stats = nfs_show_stats,
+};
+
+struct nfs_subversion nfs_v4 = {
+ .owner = THIS_MODULE,
+ .nfs_fs = &nfs4_fs_type,
+ .rpc_vers = &nfs_version4,
+ .rpc_ops = &nfs_v4_clientops,
+ .sops = &nfs4_sops,
+ .xattr = nfs4_xattr_handlers,
+};
+
+static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+ int ret = nfs_write_inode(inode, wbc);
+
+ if (ret == 0)
+ ret = pnfs_layoutcommit_inode(inode,
+ wbc->sync_mode == WB_SYNC_ALL);
+ return ret;
+}
+
+/*
+ * Clean out any remaining NFSv4 state that might be left over due
+ * to open() calls that passed nfs_atomic_lookup, but failed to call
+ * nfs_open().
+ */
+static void nfs4_evict_inode(struct inode *inode)
+{
+ truncate_inode_pages_final(&inode->i_data);
+ clear_inode(inode);
+ /* If we are holding a delegation, return and free it */
+ nfs_inode_evict_delegation(inode);
+ /* Note that above delegreturn would trigger pnfs return-on-close */
+ pnfs_return_layout(inode);
+ pnfs_destroy_layout_final(NFS_I(inode));
+ /* First call standard NFS clear_inode() code */
+ nfs_clear_inode(inode);
+ nfs4_xattr_cache_zap(inode);
+}
+
+struct nfs_referral_count {
+ struct list_head list;
+ const struct task_struct *task;
+ unsigned int referral_count;
+};
+
+static LIST_HEAD(nfs_referral_count_list);
+static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
+
+static struct nfs_referral_count *nfs_find_referral_count(void)
+{
+ struct nfs_referral_count *p;
+
+ list_for_each_entry(p, &nfs_referral_count_list, list) {
+ if (p->task == current)
+ return p;
+ }
+ return NULL;
+}
+
+#define NFS_MAX_NESTED_REFERRALS 2
+
+static int nfs_referral_loop_protect(void)
+{
+ struct nfs_referral_count *p, *new;
+ int ret = -ENOMEM;
+
+ new = kmalloc(sizeof(*new), GFP_KERNEL);
+ if (!new)
+ goto out;
+ new->task = current;
+ new->referral_count = 1;
+
+ ret = 0;
+ spin_lock(&nfs_referral_count_list_lock);
+ p = nfs_find_referral_count();
+ if (p != NULL) {
+ if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
+ ret = -ELOOP;
+ else
+ p->referral_count++;
+ } else {
+ list_add(&new->list, &nfs_referral_count_list);
+ new = NULL;
+ }
+ spin_unlock(&nfs_referral_count_list_lock);
+ kfree(new);
+out:
+ return ret;
+}
+
+static void nfs_referral_loop_unprotect(void)
+{
+ struct nfs_referral_count *p;
+
+ spin_lock(&nfs_referral_count_list_lock);
+ p = nfs_find_referral_count();
+ p->referral_count--;
+ if (p->referral_count == 0)
+ list_del(&p->list);
+ else
+ p = NULL;
+ spin_unlock(&nfs_referral_count_list_lock);
+ kfree(p);
+}
+
+static int do_nfs4_mount(struct nfs_server *server,
+ struct fs_context *fc,
+ const char *hostname,
+ const char *export_path)
+{
+ struct nfs_fs_context *root_ctx;
+ struct fs_context *root_fc;
+ struct vfsmount *root_mnt;
+ struct dentry *dentry;
+ size_t len;
+ int ret;
+
+ struct fs_parameter param = {
+ .key = "source",
+ .type = fs_value_is_string,
+ .dirfd = -1,
+ };
+
+ if (IS_ERR(server))
+ return PTR_ERR(server);
+
+ root_fc = vfs_dup_fs_context(fc);
+ if (IS_ERR(root_fc)) {
+ nfs_free_server(server);
+ return PTR_ERR(root_fc);
+ }
+ kfree(root_fc->source);
+ root_fc->source = NULL;
+
+ root_ctx = nfs_fc2context(root_fc);
+ root_ctx->internal = true;
+ root_ctx->server = server;
+ /* We leave export_path unset as it's not used to find the root. */
+
+ len = strlen(hostname) + 5;
+ param.string = kmalloc(len, GFP_KERNEL);
+ if (param.string == NULL) {
+ put_fs_context(root_fc);
+ return -ENOMEM;
+ }
+
+ /* Does hostname needs to be enclosed in brackets? */
+ if (strchr(hostname, ':'))
+ param.size = snprintf(param.string, len, "[%s]:/", hostname);
+ else
+ param.size = snprintf(param.string, len, "%s:/", hostname);
+ ret = vfs_parse_fs_param(root_fc, &param);
+ kfree(param.string);
+ if (ret < 0) {
+ put_fs_context(root_fc);
+ return ret;
+ }
+ root_mnt = fc_mount(root_fc);
+ put_fs_context(root_fc);
+
+ if (IS_ERR(root_mnt))
+ return PTR_ERR(root_mnt);
+
+ ret = nfs_referral_loop_protect();
+ if (ret) {
+ mntput(root_mnt);
+ return ret;
+ }
+
+ dentry = mount_subtree(root_mnt, export_path);
+ nfs_referral_loop_unprotect();
+
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
+
+ fc->root = dentry;
+ return 0;
+}
+
+int nfs4_try_get_tree(struct fs_context *fc)
+{
+ struct nfs_fs_context *ctx = nfs_fc2context(fc);
+ int err;
+
+ dfprintk(MOUNT, "--> nfs4_try_get_tree()\n");
+
+ /* We create a mount for the server's root, walk to the requested
+ * location and then create another mount for that.
+ */
+ err= do_nfs4_mount(nfs4_create_server(fc),
+ fc, ctx->nfs_server.hostname,
+ ctx->nfs_server.export_path);
+ if (err) {
+ nfs_ferrorf(fc, MOUNT, "NFS4: Couldn't follow remote path");
+ dfprintk(MOUNT, "<-- nfs4_try_get_tree() = %d [error]\n", err);
+ } else {
+ dfprintk(MOUNT, "<-- nfs4_try_get_tree() = 0\n");
+ }
+ return err;
+}
+
+/*
+ * Create an NFS4 server record on referral traversal
+ */
+int nfs4_get_referral_tree(struct fs_context *fc)
+{
+ struct nfs_fs_context *ctx = nfs_fc2context(fc);
+ int err;
+
+ dprintk("--> nfs4_referral_mount()\n");
+
+ /* create a new volume representation */
+ err = do_nfs4_mount(nfs4_create_referral_server(fc),
+ fc, ctx->nfs_server.hostname,
+ ctx->nfs_server.export_path);
+ if (err) {
+ nfs_ferrorf(fc, MOUNT, "NFS4: Couldn't follow remote path");
+ dfprintk(MOUNT, "<-- nfs4_get_referral_tree() = %d [error]\n", err);
+ } else {
+ dfprintk(MOUNT, "<-- nfs4_get_referral_tree() = 0\n");
+ }
+ return err;
+}
+
+static int __init init_nfs_v4(void)
+{
+ int err;
+
+ err = nfs_dns_resolver_init();
+ if (err)
+ goto out;
+
+ err = nfs_idmap_init();
+ if (err)
+ goto out1;
+
+#ifdef CONFIG_NFS_V4_2
+ err = nfs4_xattr_cache_init();
+ if (err)
+ goto out2;
+#endif
+
+ err = nfs4_register_sysctl();
+ if (err)
+ goto out2;
+
+#ifdef CONFIG_NFS_V4_2
+ nfs42_ssc_register_ops();
+#endif
+ register_nfs_version(&nfs_v4);
+ return 0;
+out2:
+ nfs_idmap_quit();
+out1:
+ nfs_dns_resolver_destroy();
+out:
+ return err;
+}
+
+static void __exit exit_nfs_v4(void)
+{
+ /* Not called in the _init(), conditionally loaded */
+ nfs4_pnfs_v3_ds_connect_unload();
+
+ unregister_nfs_version(&nfs_v4);
+#ifdef CONFIG_NFS_V4_2
+ nfs4_xattr_cache_exit();
+ nfs42_ssc_unregister_ops();
+#endif
+ nfs4_unregister_sysctl();
+ nfs_idmap_quit();
+ nfs_dns_resolver_destroy();
+}
+
+MODULE_LICENSE("GPL");
+
+module_init(init_nfs_v4);
+module_exit(exit_nfs_v4);